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  1. IMPALA
  2. IMPALA-5004

Switch to sorting node for large TopN queries

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Details

    • Improvement
    • Status: Resolved
    • Major
    • Resolution: Fixed
    • Impala 2.9.0
    • Impala 3.1.0
    • Frontend
    • None

    Description

      As explained by tarmstrong in IMPALA-4995:

      We should also consider switching to the sort operator for large limits. This allows it to spill. The memory requirements for TopN also are problematic for large limits, since it would allocate large vectors that are untracked and also require a large amount of contiguous memory.

      There's already logic to select TopN vs. Sort: planner/SingleNodePlanner.java#L289

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          is related to

          Bug - A problem which impairs or prevents the functions of the product. IMPALA-7777 Fix crash due to arithmetic overflows in Exchange Node

          • Major - Major loss of function.
          • Resolved
          relates to

          Improvement - An improvement or enhancement to an existing feature or task. IMPALA-3471 TopN should be able to spill

          • Minor - Minor loss of function, or other problem where easy workaround is present.
          • Open

          Bug - A problem which impairs or prevents the functions of the product. IMPALA-4995 crash when limit clause > MAX_INT

          • Blocker - Blocks development and/or testing work, production could not run
          • Resolved

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            People

              stakiar Sahil Takiar
              lv Lars Volker
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              Dates

                Created:
                Updated:
                Resolved: